Devices that drop balls and darts are used in a variety of applications. For example in cementing the darts are used to wipe drill pipe clear of cement while dropped balls on seats can be used for allowing building pressure to set tools such as liner hangers/seals that are frequently used in conjunction with equipment for running or setting a liner in existing casing. These devices can be surface mounted on cementing heads for manual or automatic operation by rig personnel or they can be located remotely from a surface location and remotely operated from the surface by fluid flow patterns or remotely actuated detents that can release a potential energy force to launch a ball.
U.S. Pat. No. 4,452,322 shows in FIG. 2 a split view of a ball retained by a sliding sleeve with a flow passage through it. Fluid flow patterns with a j-slot overcome a resisting spring force and ultimately shifts the sleeve to align a port in the sleeve with a ball for gravity release of the ball. U.S. Pat. No. 7,100,700 uses high flow rates to create axial movement to release a ball at a subterranean location that is stored out of the fluid stream until released. Various surface mounted manually operated ball droppers are illustrated in U.S. Pat. No. 6,776,228 where a fork-shaped device straddles a ball and with rotation turns the ball into the flowpath. In U.S. Pat. No. 7,802,620 a handle is turned 180 degrees to cam a ball through an outlet as shown in FIG. 2. Finally, U.S. Pat. No. 4,577,614 shows in FIG. 2 a remotely released detent that allows the potential energy of a spring to push balls out over the bias of a retaining leaf spring.
U.S. Pat. No. 7,299,880 shows a bypass that stays open to allow running of casing without surging the well where the bypass can be closed in the event of a well pressure event.
Some completion assemblies require torque transmitting capabilities and in some applications the ability to drop a ball on a seat if an earlier dropped dart fails to seat so a tool can be set. The present invention combines some of these capabilities by allowing release of a wiper plug with a pickup force. The pickup force allows the plug retainers to pivot to release a dart and at the same time obstruct a flow bypass that allowed flow around the dart before it was released. While running in and until the dart is released the tool components are rotationally locked at a first location and the lock at the first location releases when the plug is launched with an axial pick up force. During the pickup to release the dart a trapped ball in an axial slot in a mandrel is aligned with a mandrel exit hole where relative rotation then can cam the ball toward the exit hole and into the mandrel bore. The released ball can be a backup to set the same tool the dart was intended to set or it can set another tool altogether. The further axial movement to release the ball also engages an upper rotational lock to allow torque transmission for operation of other tools.
Those skilled in the art will more readily appreciate additional aspects of the present invention from a review of the detailed description of the preferred embodiment and the associated drawings while recognizing that the full scope of the invention is to be determined from the appended claims.